Electric circuit breaker



Nov. 189 1952 w. n. BoLLER ETAL ELECTRIC CIRCUIT BREAKER 6 Sheets-Sheet l Filed June 10, 1948 lill I Tm .M u DEN .m N TLBT n NLED O B n T @LHA i... mnmDEL A NRM n:EN MHT umm., y WEB Nov. 18, 1952 w. D. BoLLER ETAL 2,618,716 ELECTRIC CIRCUIT BREAKER Filed June 10, 1948 6 Sheets-Sheet 2 #suman as /B INVENTOHS 56 WILLIAM l2 BOLL ER I4 vanne/v n. Benner 52 m1. ren fla/v51' ST Eon/N w. unam-mr Ar-rnmvElS Nov. 18, 1952 w. D. BoLLl-:R ETA'.

ELECTRIC CIRCUIT BREAKER.

Sheets-Shee 3 Filed June 10, 1948 Nov. 18, 1952 w. D. BOLLER ETAL ELECTRIC CIRCUIT BREAKER Filed June 10, 1948 Nov. 18, 1952 w. D, BOLLER ETAL 2,518,716

ELECTRIC CIRCUIT BREAKER Filed June l0, 1948 6 Sheets-Sheet 5 /IWE/YTOHS WILL/4M D. BULLE/ WARREN D BEHHLEY WALTER ERNST EDWIN W LANMEIER Y ATTORNEYS Nov. 18, 1952 w.D.BoL1 ER ErAL 2,618,716

ELECTRIC CIRCUIT BREAKER Filed June 10. 1948 6 Sheets-Sheet 6 luvlNraRs WILLIAM D. BOLLEE WARREN D. BEEKLEY WALTER ERNST @EDWIN W LHNDMEEE VWA 'maw Patented Nov. 18, 1952 f UNITED STATES PATENT OFFICE ELECTRIC CIRCUIT BREAKER- Kentucky Application June 10, 1948, Serial No. 32,204

6 Claims. l

This invention relates to circuit breakers, and is concerned primarily with a combination switch and circuit breaker intended to control the circuits in homes and comparable places.

At the present time, the electrical installations for homes, business establishments, and other places making use of the current supply that is made available by the electric companies includes one or more circuits, each of which embraces a fuse and sometimes a switch associated therewith. When the circuit is overloaded or a short circuit develops, the fuse burns out in a well-known manner and must be replaced before service can be restored.

The present invention has in view as its foremost objective the provision of a combination switch and circuit breaker which is intended to replace the fuse and switch heretofore employed in controlling such circuits.

Under practical conditions, a plurality of circuits are ordinarily included in electrical installations of the type with which this invention is concerned and a further object of the invention is the provision of a combination circuit breaker and switch which is susceptible of being assembled in multiple or gangs with each unit controlling one circuit.

In the known combination units of the type intended to be improved by this invention, it has been the practice to provide a pair of contacts for controlling the circuit. When these contacts are in engagement, the circuit is closed and when they are spaced apart, the circuit is open. Usually one of these contacts is iixed and the other is movable. The present invention has in view as an important object the provision of a combination switch and circuit breaker of the type indicated in which both of the contacts are movable. This arrangement presents certain denite advantages. It is possible to provide for the movement of one contact into opened or closed position under the influence of a manually operable lever While the other contact is placed under the control I" the circuit conditions so as to be moved into opened position `clean a further object of the invention is the provision ci a combination switch and circuit breaker of the type indicated in which the contacts are separated with a wiping action in contrast to a direct pull apart.

In circuit breakers of the type with which this invention is concerned, the opening of the contacts is placed under the control of a bimetallic thermostat together with a so-called rupture" magnet that is affected by the current conditions to vary the strength thereof. The bimetallic thermostat is heated by overload conditions and when a predetermined condition is reached opens the contacts, whereas the rupture magnet is affected by a short circuit or other comparable instantaneous condition to immediately open the contacts. It has been the practice to mount the rupture magnet on the thermostat so that it is movable therewith. However, the present invention, in one embodiment, contemplates mounting of the rupture magnet in a xed position in the casing and an armature which cooperates therewith is carried by a, latch which controls relative movement of the contacts. This arrangement presents certain advantages not only as to ease of assembly but also in sureness of operation. With this arrangement, the rupture magnet is mounted with no physical connection between it and the bimetallic thermostat.

Still another object of the invention is the provision, in a combination switch and circuit breaker of the type aforesaid, of a novel assembly of a latch, keeper piece, and rivets which is highly simplified as compared to anything heretofore provided for this purpose.

Various other more detailed objects and advantages of the invention such as arise in carrying out the above noted ideas in a practical embodiment will in part become apparent and in part be hereinafter stated as the description of the invention proceeds.

For a full and more complete understanding of the invention reference may be had to the following description and accompanying drawings wherein:

Figure 1 is a longitudinal vertical section through a combination switch and circuit breaker designed in accordance with the precepts of this invention and showing the unit in manually closed position;

Figure 2 is a sectional View similar to Figure 1 showing the unit in the manually opened position;

Figure 3 is another view similar to Figures 1 and 2 showing the unit in the opened position as caused by circuit conditions;

Figure 4 is a vertical section taken on a plane normal to the showing of Figures l, 2 and 3;

Figure 5 is an enlarged detail view showing embodiment;

the rocker carrying one of the contacts in plan and the casing in section;

Figure 6 is another detailed view taken on a horizontal plane as represented by the line B-B on Figure 1 j Figure 7 is a View similar to Figure 1 of a modified form of the invention showing the unit in its manually closed position;

Figure 8 is a view similar to Figure 2 showing the modned form of the unit in the'manually closed position; Y Y

Figure 9 is a View similar'` to Figure 3 yshowing the modied unit of Figures 7 and 8` in the opened position caused by circuitY conditions;

Figure 10 is a sectional'view similar'to Figure 4 of the modified form of Figures 7, 8, and 9 and is taken on a vertical plane normal to the showing of Figures 7, 8 and 9;

Figure 11 is a detailed section taken about on theplanes represented'by the lines II-II of Figure 9;

' about on the plane represented by the line IZ-I 2 on Figure 9; Y

Figure 13 is another enlarged detailed section taken about on the plane represented by the line I3-I3 on Figure '7;

Figure 14 is a detailed perspective of the cover plate per se of the modified embodiment;

FigureV 15 is a detailed perspective of the casing per se of the modified embodiment;

Figure 16 is a detailed perspective of the operating lever ofthe modified embodiment;

Figure 17 is a detailed perspective of the bimetallic thermostat and elements immediately associated therewith ofv the modified embodiment; n

Figure 18 isa detailed perspective ofV one of the terminal vplates of the modied embodiment;

Figure 19 is a detailed perspective of one of the contact carrying members of the modified Figure 20 is anotherl detailed perspective of the contact carrying' rocker arm of the modi- Preferred embodiment The preferred embodiment of the invention is illustrated in Figures 1 to 6, inclusive. In these views there is shown a casing which is referred to in its entirety by the reference character C and which is made from an appropriate material having good insulating properties and which is susceptible of being molded into the desired structural formation. There are available on the public market many synthetic plastics which will fulll these qualifications. Among these is the phenol condensation product known as Bakelite.

The casing C comprises a main side wall l ID, a top wall II, a bottom wall I2, and end walls f I3 and I4 which are spaced inwardly from the end edges of theside wall III. All of these Walls are integrally joined andthe completed struc-1 Vthickened wall structure Il..

4 ture provides free end portions of the side wall ID which are represented at I5 and I6 and immediately beneath which are the thickened Wall structures I7 and I8.

Thev end wall I3 is formed'with aslot I9 which defines an outer panel' 23 which isrelatively long and the end edge of which is spaced from the This slot I9 also denes an inner panel 2i which is relatively short and the end edge of which deiines an opening at 22. A terminal plate 23 is formed at one end with an inclined ange 24 which is received in the slot I9. This terminal plate 23 is also formedvwith a neck 25 which is countersunk in a recess formed in the thickened wall structure I'I. This neck 25 is interiorly threaded as represented at 23 to accommodate a binding post. The thickened wall structure I7 is also provided with a recess 21 beneath the threaded bore 26v to allow for screwing the binding post (not illustrated) home.

Referring now to the thickened wall structure I8 and end wall I3; it will vbe noted' that these two elements are spaced apart by an irregularly shaped slot 28. The wall structure I8 is formed with a `recess 29 that is counterbored as indicated at 39. Another terminal plate 3|' has a neck 32 that is received in the counterborev and the bore of which is threaded asA indicated at 33, the threaded borebeing located opposite to the recess 29. The threaded bore 33fand recess 29 accommodate another bindingpost. The terminal plate 3I Vis formed with an irregularly shaped part 33 that corresponds to and is received in the slot 2B. integrallyY connected to this part 3d is a flange 35 whichis positioned within the chamber enclosed by end walls I3 and It.

An adjusting screw 36 is received in apassage 31 formed in the thickened wall structure I8. This screw 36 has a head 38 which is positioned within an enlarged recess 39 that communicates with the bore 37. This head 38 may be slotted to accommodate a tool such as a screw driver.

The thickened Wall structure I8 is formed with a recess 40 which communicates with the inner chamber of the casing and the Vbore 31.' The adjusting screw 35 extends into this recess and immediately adjacent to the thickenedwall I8 is formed with an annular groove dl which receives a washer d2. This washer 62 andthe head 38 hold the screw 36 against longitudinal movement. The free inner end of the screw 3S is threaded and screwed into an openingv 43 formed in the ange 35 and also into an opening ed Iformed in the end portion 450i a bimetallic thermostat 45, this end portion being oset from the main par-t of the bimetallic thermostat by a shoulder t?. It willbe noted that this end portion t5 snugly engages the iiange 35 of the terminal plate and is spot welded thereto. Y Extending inwardly from the end wall I4 into the inner chamber are a pair oflugs 48 Aande!! which are integrally formed with'ithewall I4. The opposing corners of these lugs yllandAS are cut away to provide recesses whichjreceive a rupture magnet 59. This magnet lisjofethe U- shaped cross-section illustrated in Figure 6 and has legs 5I and 52, theV outer aces'of Wlichare imbedded in the side wall IIland coverto be later described. These side legs 5I vand 52; together with the base, dene ai recess 53 through which the bimetal 6 passes. It is evidenti-that current passing through'the 4bimetal 46 will-'be effective on the rupture 4magnet-591:0 varythe strength thereof for circuit rupturing purposes as will be later described.

A keeper piece 54 has its lower end anchored to the end part 45 of the bimetal 46 in any preferred manner such as by being spot welded thereto. The upper end of this keeper piece takes the form of a hook 55, the bill of which overlaps the end of th-e bimetalli-c thermostat 46. A latch member 56 which also functions as an amature for the magnet 5U is secured to this keeper piece 54. This latch member 56 is made from a metal having the required magnetic properties and i-t will be noted that a detent 51 is struck therefrom as by a metal stamping operation. The anchorage between the latch 56 and keeper piece 54 is effected by punching a pair of recesses 58 in one face of the latch 56. This forms small protuberances 59 on the opposite face. The keeper piece 54 is formed with openings which receive these protuberances 59. After Ithe protu-berances 59 pass through the openings they are peaned over to form what are in effect rivet heads 60.

The bottom wall |2 is formed with an inclined surface at 6| which opens into the inner chamber and which terminates at its lower end in a shoulder 62. A permanent magnet 63 o-f U- shaped formation has its base received on the inclined surface 6|. The side legs of the magnet 63 have outer faces which are received in recesses 64 and 65 formed in the casing and cover, respectively. Also, fitted in these recesses and surrounding the sides of the magnet 63 are berboard frames 66 and 61 which are held in position by lugs 68 that are formed integral with the cover and casing respectively and which have end portions that overlaps the fiberboard frames.

The permanent magnet 63 is intended for arc suppressing purposes as will be later described and the fiberboard frames 66 and 61 accommodate -the arc deposits which are formed by carbonizing which is an incident to the arc suppression. At this point, it is well to note that the strength of the permanent magnet 63 is related `to the magnitude of the arc which will be created by the break of the contacts. The magnitude of the arc depends on .the speed at which the contacts are broken and the strength of the current. There are now available permanent magnets having this required strength. Among such are the magnets sold under the trade name Alnico.

Extending downwardly from the top wall into the inner chamber is a projection v65! having an end face at 10 which is adapted to ac-t as an abutment or stop as will be later described. This -top wa'll is also formed with an opening at 1|, the end walls of which are formed as the cylindrical surfaces illustrated in the drawing. A manually operable lever 12 is formed with diametrically opposite projections 13 a-t each side thereof and these projections act as trunnions or pivots for mounting the lever 12. They are received in recesses 14 formed in :the casing and cover, respectively, along the side edges of the opening 1|. This lever 12 carries an arcuate Wall structure 15 which is complemental to and snugly received within the curved end walls of the opening 1|. This wall structure 15 completely closes the opening and at the same time permits swinging of the lever 12 about the trunnions 13 as a pivotal mounting.

Extending inwardly into the inner chamber and carried by the lever 12 are a pair of legs 16 which are spaced apart with the lower free edge of each leg formed with a notch 11. The 1nner face of each leg 16 is also formed with a V-shaped notch presenting inclined faces 8 and 1 that terminate at the lower edges of the leg. Thus the V-shaped notches are wider than the notches 11 and the faces 8 and 1 are adapted to function as stops in a manner now to be described.

A contact carrier 18 is of bifurcated construction defining a pair of legs 19 and 80 which are integrally joined at the bottom and from each of which outstands a pin 8| that is received in the respective notch 11. The lower end of this contact carrier 18 carries a contact 82. A tension coil spring 83 has its lower end anchored to the contact carrier 18 as represented at 84. The other end of this spring 83 is anchored to a rocker now to be described. It is evident that movement of carrier 18 about pins 8| is limited lby the stop faces 8 and 1 -on the legs 16.

A rocker 85 has trunnions 86 extending from opposite sides thereof and these trunnions are journaled in the cover and casing respectively as is brought out in Figure 5. The lower end of this rocker 85 carries a contact 81 which is complemental to and adapted to engage the contact 82. It is notable that the contact 82 is moved away from the contact 81 by a wiping action caused by the straightening of the level` 12 and carrier 18. This rocker is made of a good conducting material such as copper and its upper end is reduced in size to provide for the mounting of an insulating member 88 thereon. This'insulating member may take the form of a glass ring and it functions as an insulated anchorage for the upper end of the spring 83. Mounted on opposite faces of the rocker 85 are a pair of brackets 89 and 90, the connection being effected by spot or resistance welding; the hole shown at SI in Figure 5 serving as a locating point. Each of these brackets 89 and 99 is formed with a cam surface S which is adapted to cooperate with the respective side edge 92 of the leg 16.

The rocker 85 also carries an outwardly extending projection 93 having a face at 94 that is adapted. to engage the abutment face 18. A flexible conductor 95 connects this projection 93 on the rocker 85 with the bimetal 46. Another flexible conductor 95 connects the contact carrier 18 with the terminal plate 23 passing through the opening 22 and being joined to the flange 24 in any preferred manner as by soldering.

The cover is shown at 91 and is preferably made from an insulating material having transparent properties and which is susceptible of being tinted to a desired shade for the purpose of designating the capacity of the unit. It 'will be notedthat the end wall I3, thickened wall structure I1, thickened wall structure I8, and projection 66 are formed with openings, all of which are designated 98. The cover 91 is formed with openings that align with openings 98 and tubular fastening members 99 pass through the aligned openings. The ends of these tubular fasteners may be peaned outwardly in a wellknown manner to provide what is in effect a riveted connection.

Operation preferred embodiment In outlining the operation of the above described circuit breaker and switch unit, attention is rst called to Figure l which depicts the condition of the unit when the circuit is closed. It will be noted that in this position the spring 83 being disposed at one side of the pins 8| urges the contact 82 against the contact 81 because movement of the rocker is prevented by the defascisme plate 3| throughthe flangeV 35 thereof to the bimetal 6,rconductor-95 connects the latter tothe -f rocker. lThecurrent then passes fromtherocker fthrough contacts 8l Vand'82 tocontactcarri'er-'IS 'and from ythere through the *conductor-96 to the terminal plate v23.

fliigure 2 depicts the unit in the condition in which the circuit has been opened by -manualoperation of the leverlZ. It willbe noted that Vthe contacts 82- and` 8l have been moved apart with a wiping'action to break thev circuit. This has been achievedby movement oi the contact 82 alone becausefthe latch 57 still holds the rocker rThis causes It will be noted that this movement on the part of the lever 'i2 is accommodated Ybecause there is anappreciable-space between the cam surfaces 92 and S. Thus, the lever may be moved'without affecting the rocker 85. In this 'jpositionthe upper end of the carrier 'i8 engages 'the stop' face 8.

A'ligure' 3 shows the condition of the unit which has been -caused by circuit conditions to rupture *the circuit by moving both the contacts-32 and 8l. The circuit condition might either be an overloadwhich affects 'the bimetallicthermostat t 45 so as to move the keeper piece -trand latch 55 carried thereby so that the detent 5? iswithydrawn from the projection 93 or it maybe a short circuit which will cause the rupture magnet "-59 to have this eiect on the latch member 55 which, it will be recalled, is also an armature for the magnet. Regardless of' which may be the cause, when the detent is withdrawn from the projection 93, the springs being always under vtension rotates the rocker B'in a counterclock- "wise direction (speaking with reference to the showing of the drawings) and this movement is continued until the surface 91% engages the abut l ment surface li). As this movement takes place, Athe-contact 8l of course moves away from lthe vcontactZ.v At the same time,the pivot pin El will be'eiiected by the movement of the rocker arm to change its relative position with respect i to the spring 83 and instead of beingpositioned on the left-hand side, Aas in the circuit closing posi- Y tion, its relative position is changed to therighthand side and the contact 82 is also moved in Y the direction away from the Contact 8l.

-As the contacts 62v and t? move away from each other there ordinarily would be a tendency to arcing. However, this'arcing is suppressed by the permanent magnet 53.

The position oi the leveivlZ` afterl the circuit has been ruptured by circuit conditions is shown in Figure 3 which, it will be noted, is substantially intermediate the positions of Figures 1 and 1 In this position-the cani surfaces' 92 and 2 are inclose-proximity. Thus, when it is desired to'reset the Yunit to close the circuit thev lever 'l2 must first be swung in aY counterclockwise 'direction to'move the rocker Sein a clockwise Ydirection and againY place the-projection 93 under `ltheretaining-eiect of the-detent 5l of'thelatch- 5S. "The .lever l2V may-ithenebeswungflintothe circuit closed position shownin Figure -1.

" First modification ".An alternative embodiment of Vthe invention'is illustrated in Figures 7"to 21, inclusive. `-Aside from minor details which amount to little more than'change in design. the onlyrealdiierences vbetween the Vperferred'iorm oi the" invention shown inFigures l to- 6 andthis alternative Vernbodiment is in the mounting of the rupture niagnet'and the construction Vof the manuallyjoperable lever in which the arcuateconstruction of the preferred embodiment ha's'been omitted.

" AWithout repeating a description Aof the various elements 4which have been'described in connection with Figures 1 to 6J inclusive; it is noted that the vterminal plate 2S and end wall structure :'13 are of a'slightly dierent orm.""The.flange"24 of the plate is formed with an inturnedjlip iti that projects into.' the inner 'chamberand which is connected by the flexible conductori tothe contact carrier '18. There is also a's'light diii'erence in the construction ofA the terminal plate Si and the manner inrwhichit isinou'nt'ed inthe end wall It. Y It-will be notedthat the irregular slot 28 and struct-ure 3Q have been replaced by a straight slot 192 and a corresponding straight wall structure.

Instead oi being fixedly mounted in .the end wall liras in the form of Figures 1 to 6, inclusive, a rupture magnet E63 is mounted on the bimetal .by a rivet shown atlfl. `The armaturecfor the magnet is shown at H and is anchoredto face of the keeper piece 5G.- The vopposite face oi the keeper piece' carries a `latch H3G. A rivet extends through aligned openings in the latch itt, keeper piece 5i, and armaturev E65 to Vmaintain the assembled relation. Latchfiil has a detent it? which corresponds to the detent Yhe manually operable lever 12 isshown with the arcuate wall structure l5 omitted. VThis means thatftheopening at |33 which corresponds to the opening "di also is devoid'of the `arcuate There is another dili'erence in the` construction of the upper portion ofthe rocker. Insteadzzof having this entire upper portion ofrconducting metal and using the glass bead 88, the upperpart of the rocker 85 is formed of insulating material such las `represented atm@ in Figures 7, 8, 9,-' and 20. rI'he upper end of the spring lis anchored to this arm EES by'being fitted in the notch iHO. Upon referring particularly tov Figure 19, it' will benotedthat the'contact carrier it is of a bifurcated construction and'small tabs I Il are struck from each side ofthe central slot.` These tabs engage the leg i6 and prevent lateral'or sidewise movement on the part of the contact carrier-78. This same arrangement is also employed in'the preferred embodiment although itV is not illustra-ted.

'Operation first modification The operation of the alternative embodiment is substantially that of the preferred embodi- 1 ment. Figure 'l depicts the condition of the varirous vparts in circuit closing position. Figure; 8

shows the parts whenv the circuit has been manually opened, being substantially the same as Figure 2. Figure 9 corresponds to Figure 3 and shows the circuit as having beenruptured.by circuit conditions. In this view it willibe noted that the detent lllihas` been withdrawnfrom the projection 93 so that the rocker 85 has been actuated by the spring 83 and moved into the position illustrated with the movement limited by the abutment 10.

Second modification A second modification of the invention is illustrated in Figure 22. It will be noted that this view is confined to a showing of the operating lever and contact carrier, rocker, spring and magnet. The remainder of the structure in which this assembly is included will be substantially the same as that described for other forms of the invention.

Referring now to Figure 22 a lever is shown at 236 and this lever is provided with a pivotal mounting in the form of trunnions 231 which are adapted tobe imbedded in the casing structure. A contact carrier 238 includes spaced side bars 239 and 240 which are joined at the bottom by a bottom wall 24| from which depends a tab 242 that carries the contact 243. A toggle link 244 is pivotally connected to the side bar 239 as shown at 245 and its upper end is formed with a notch that receives one of the trunnions 231. Likewise, another toggle link 246 is pivotally connected to the upper end of the bar 240 and the free end of the link 246 is formed with a notch that receives a trunnion 231.

A rocker is shown at 241 as comprising a pair of plates which are in abutting engagement below the pivot pin 248 and spaced apart above this pivot pin. This spacing provides arms 249 and 250. A contact 25| is carried at the lower end of the rocker 241 and is adapted to engage the contact 243. Both of these contacts are mounted in close proximity to a permanent arc suppressing magnet 252.

A coil tension spring 253 has its upper end anchored to the arm 249 of the rocker 241 as indicated at 254, while its lower end is anchored to the contact carrier 238 as represented by the dotted lines.

It is evident that the assembly shown in Figure 22 may be employed with the usual arrangement of detent, bimetallic thermostat, and electromagnet for causing the rocker 241 to swing on its pivot 248 when a predetermined circuit condition occurs. This rotative movement will be caused by the spring 253 and will take place in a counterclockwise direction. As the rocker rotates the arm 249 will also rotate and move the anchorage for the upper end or the spring past the center 245 of the toggle made up of the carrier 238 and links 242 and 246. The spring 253 will then tend to swing the carrier 29| in a clockwise direction. Thus, the contacts 243 and 25| are separated.

For manual operation the lever 23B is rotated on its axis 231 and the center line of the pivots 245 move to one side or the other of the spring 253, thus causing the latter to bias the carrier either in a counterclookwise direction which urges the contacts in engagement or in a clockwise direction which separates them.

The arm 259 cooperates with the construction now illustrated in resetting the rocker 241 after a rupture has occurred and the circuit condition which caused the rupture removed.

Third modification A third modification of the invention is shown in Figure 23. In this gure it will be noted that the contact carrier 290 is pivotally connected at 29| to a lever 292. The lower end of the carrier 290 is provided with a contact 293. A rocker 294 10 is pivotally mounted as shown at 295 to the casing structure. The lower end of this rocker is provided with a contact 296. The rocker 294 is provided with two arms above the pivot 295, one being shown at 291, the other at 298, the latter being a reset arm.

A tension coil spring 299 has its lower end anchored to the carrier 290 as shown at 300 and its upper end to the arm 291 of the rocker as shown at 30|. The rocker 294 is provided with a stop 302 with which is associated the usual detent 303. The detent 303 is controlled by a bimetallic thermostat and a magnet in the manner heretofore described. A stop shown at 304 limits movement of the carrier 290 in a counterclockwise direction.

Operation third modification With the detent 303 cooperating with the stop 302 to hold the rocker 294 against rotation, the lever 292 may be swung to move the center 29| to one side or the other of the spring 299, thereby causing the latter to bias the contact 293 in either open or closed position.

When a predetermined circuit condition occurs the short circuit or overload will cause the detent 303 to be withdrawn from the stop 302. The spring 299 will now rotate the rocker 294 in a counterclockwise direction to withdraw the contact 29S from the contact 293. Movement of the carrier 290 is prevented by the stop 304. After the connection at 30| on the arm 291 has moved suiiiciently far to cause the spring 299 to pass to the other side of the center 29| the spring 299 will then be effective to move the carrier 290 in a clockwise direction. Thus the rocker 294 is moved in a counterclockwise direction and the carrier 290 in a clockwise direction.

On the reset operation the lever 292 is swung so that the lower portion thereof engages the reset arm 298, whereupon the rocker 294 is moved in a clockwise direction to again bring the stop 302 into effective engagement with the detent 303.

While preferred specific embodiments of the invention are hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions, devices, and mechanisms illustrated and described because various modications of these details may be provided in putting the invention into practice within the purview of the appended claims.

What is claimed is:

1. In a combination switch and circuit breaker, a casing, a rocker pivotally mounted in said casing, a contact carried by said rocker, a pivotally mounted contact carrier, a contact carried by said carrier and adapted to engage the contact carried by said rocker, an over-center tension spring having its opposite ends connected to said rocker and said contact carrier to bias the contacts carried by the rocker and carrier toward and away from one another, latch means cooperating with said rocker, instrumentalities under the control of predetermined circuit conditions operatively connected to said latch means, and amanually operable lever for changing the relative positions of the rocker and pivot point of the contact carrier and thereby coincidentally position the spring to exert over-center tensions biasing the rocker and contact carrier to respective contact engaging and disengaging positions.

2. In a combination switch and circuit breaker including a pair of relatively movable contacts as a circuit controlling means, manually operable mechanism for moving one of said contacts, automatic means responsive to predetermined circuit .conditions :for `moving bothioi said contacts rapartxin `substantially'opposite directions. said emeansvcomprising arocker carrying one of vsaid contacts, spring'means tensionally interconnectzing said ,rocker and said manually operable mechanism to urge said rocker in a direction to separate said contacts, and a detent associated with said rocker 'preventingl such separating movement.

,3. A circuit breaker and switch comprising, a .contactcarrieny a manually operable lever constitutinga Vshiftable pivotal mounting for said contactcarrer, a, .pivotally mounted rocker, and a tension spring, the said tension spring interconnecting said contact carrier and rocker in opposite overcenter positions in relation to said contact carrier in response 'to rocking movements .of -said rocker infopposite. directions, and manual operation of said lever causing shifting: of the .pivotal axis of the contact carrier to respective over-.center positions in relation to said spring, said spring .biasing said. l rocker toward pivotal movement in one direction, a latch for restrainingA said rocker against such movement, :said latch beingl releasable in resp-onse to overload ,circuit conditions, and cooperable contacts carried by said rocker vand contact carrier, said con- .tacts .being moved into and out of engagement With one another in response to movements of said contact carrier and rocker eiectuated through lthe 'said over-center positioning or" said spring.

14. .A' combination switch `and circuit breaker Comprising, a pivotally mounted rocker having a contactatione side of its pivotal axis, a tension spring connected to the rocker at the opposite side of its pivotal axis, a pivotally mounted contact carrier having a contact cooperable with the contacten said carrier, the oppositefend of said vspring being connected to said contact carrieriin such position -that When said contacts are inengagement the force axis of said spring passes to one side ofthe pivot axis of the contact carrier, whereby-the tension spring biases the contacts Ainto engagement, and the'point of connection ofY thespring to the rocker being so positionedinr relation to the pivotal axis of the contact carrier that pivotal movement of the rocker causes relativey shiftingof the force axis of the springto the opposite side of the pivotal axis of the contact carrier, to bias the contacts toward disengagement, a manually operable lever for shifting the pivotal axis of the contact carrier from one side of the spring to the other when the contacts are in engagement, whereby the contacts maybe disengaged .independently of, piv- Qtallmovement, of Vthe rocker, and means releasable in event of circuit overload conditions, for normally restraining therocker against pivotal movement.

5. Aswitch comprising, a pivotaliy mounted contact carrier,y a tension spring connected there- 110, Ameansgincluding a pivotally mounted rocker t0 which said. tension spring is connected, for effecting. over-center movement yof said spring in relation to, said contact carrier and thereby producing snapaction movement of said con- .tact carrier, and: a :manually operable vlever for shifting thepivotalaxis ;of saidy contact carrier into over-'center relation to said springand thereby produce snap action movement of said contact carrier independently of pivotal movement of said rocker, the said .rocker and contact carrier having cooperable contacts mounted thereby -for engagement Aand disengagement with one another in consequence to the snap action` movements .of said carrier.

6. A combination `svvitch and circuit breaker comprising, a toggle switch elementincluding a pivotally mounted contactV carrier, acontacton said carrier, a tension spring having one end connected tothe contact carrier, and a .manually operable .lever forshifting .the vpivotal axis Iof the contact carrier .to opposite lvsides of .the .force axis of thetension spring, and aprotectiveoverload release device in cooperative association with said toggle switch elements, comprisingla latch, means. Vresponsive torcircuit overload .for releasing said latch, apivotally mountedrocker., a contact carried by the rocker at one-side of its pivotal axis for cooperable engagement with the Contact on said carrier, the saidY spring having its other end tensionally connected to the rocker at `the other side of itspivotalaxisfor biasing the rocker against the latch, and the point of connection of the spring'to the rocker Vbei-ng related to the pivotal point vof the contact carrier, when thecontacts are engaged, to hcause movement of the force axis of the spring from one side of the pivot of the carrier to the other side thereofwhen the rocker moves pivotally in response to its release by rthe latch and thereby separates the contacts.

' WILLIAM DJBOLLER.

WARREN DQBERKLEY. WALTER ERNST. EDWIN W. LANDMEIER.

' REFERENCES CITED The following references are of record in the file of this patent:

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